The present invention relates to a unit for supplying products to a manufacturing machine.
In particular, the present invention relates to a unit for supplying small, compact products, and designed for installation between two manufacturing machines, one of which, located downstream from the supply unit, presents a lower operating speed as compared with the upstream machine.
In the following description, specific reference is made, purely by way of example, to a unit for supplying chocolates and installed between a chocolate manufacturing and wrapping machine.
Chocolate manufacturing systems are known to feature manufacturing machines having a number of outputs, to each of which the chocolates are fed at a first given speed and transferred, via an intermediate supply unit, on to the input conveyor of one or more wrapping machines, the input conveyor of which operates in time with the wrapping members on the wrapping machine and at a second speed lower than said first speed.
The supply unit, usually consisting of a conveyor belt, is normally set to such a speed that the chocolates fed on to it off the manufacturing machine are spaced a given distance apart.
Naturally, if the input conveyor to the wrapping machine is operated at a slower speed than the supply unit, the distance between adjacent chocolates on the input conveyor is shortened. The difference between the two speeds may reach a critical point at which the chocolates on the input conveyor actually contact one another, or an even more critical point at which the continuous stream of chocolates on the input conveyor to the wrapping machine extends as far back as the supply unit conveyor, the sliding belt of which tends to damage the underside of the chocolates. Moreover, the scraps of chocolate so produced may melt in contact with the supply unit belt, thus resulting in frequent stoppages of the entire system for cleaning and maintenance.
To overcome the above drawback, the supply unit may consist of a pneumatic conveyor, for example, of the type described and claimed in Canadian Patent N.903140. In this case, each chocolate could be fed forward on a respective air cushion defined by a number of nozzles formed through a bottom plate on the conveyor and so designed as to emit an a r jet comprising two components, one directed upwards and the other inclined slightly forward in the traveling direction of the products.
When applied to two machines of different capacity, a pneumatic conveyor of the aforementioned type provides for effectively supporting the chocolates as they are fed forward, bu not for supporting them pneumatically in a stationary position over the perforated plate, in the event the difference in the speed of the two machines exceeds said critical value. When stationary, in fact, the chocolates tend to vibrate against one another, thus resulting in damage.